WO2011008159A1 - Method for adding oxygen to a liquid absorbent in a device for purifying gas - Google Patents
Method for adding oxygen to a liquid absorbent in a device for purifying gas Download PDFInfo
- Publication number
- WO2011008159A1 WO2011008159A1 PCT/SE2010/050840 SE2010050840W WO2011008159A1 WO 2011008159 A1 WO2011008159 A1 WO 2011008159A1 SE 2010050840 W SE2010050840 W SE 2010050840W WO 2011008159 A1 WO2011008159 A1 WO 2011008159A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- absorbent
- gas
- caused
- liquid
- point
- Prior art date
Links
- 239000002250 absorbent Substances 0.000 title claims abstract description 95
- 230000002745 absorbent Effects 0.000 title claims abstract description 95
- 239000007789 gas Substances 0.000 title claims abstract description 76
- 239000007788 liquid Substances 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 23
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 21
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 21
- 239000001301 oxygen Substances 0.000 title claims abstract description 21
- 238000000926 separation method Methods 0.000 claims abstract description 15
- 150000001875 compounds Chemical class 0.000 claims abstract description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 19
- 239000003546 flue gas Substances 0.000 claims description 17
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 9
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 9
- 239000004571 lime Substances 0.000 claims description 9
- 229910052757 nitrogen Inorganic materials 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 229910052925 anhydrite Inorganic materials 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 235000019738 Limestone Nutrition 0.000 claims description 3
- 239000006028 limestone Substances 0.000 claims description 3
- 230000009466 transformation Effects 0.000 claims 3
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 20
- 238000010791 quenching Methods 0.000 description 20
- 230000000171 quenching effect Effects 0.000 description 20
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 11
- 235000010269 sulphur dioxide Nutrition 0.000 description 8
- 238000011049 filling Methods 0.000 description 7
- 238000000746 purification Methods 0.000 description 7
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000007921 spray Substances 0.000 description 6
- 239000001569 carbon dioxide Substances 0.000 description 5
- 229910052602 gypsum Inorganic materials 0.000 description 5
- 239000010440 gypsum Substances 0.000 description 5
- 239000007800 oxidant agent Substances 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000003344 environmental pollutant Substances 0.000 description 4
- 239000000945 filler Substances 0.000 description 4
- 239000002803 fossil fuel Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 231100000719 pollutant Toxicity 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 239000005864 Sulphur Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000004291 sulphur dioxide Substances 0.000 description 3
- 238000009736 wetting Methods 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000010073 coating (rubber) Methods 0.000 description 1
- 239000004567 concrete Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- 239000007792 gaseous phase Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/18—Absorbing units; Liquid distributors therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
- B01D53/504—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
- B01D53/78—Liquid phase processes with gas-liquid contact
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
- B01D53/79—Injecting reactants
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/10—Oxidants
- B01D2251/11—Air
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/40—Alkaline earth metal or magnesium compounds
- B01D2251/404—Alkaline earth metal or magnesium compounds of calcium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/60—Inorganic bases or salts
- B01D2251/606—Carbonates
Definitions
- the present invention relates to a method for adding oxygen to a liquid absorbent in a device for purifying gas, which absorbent comprises at least one compound capable of reacting with oxygen, and is characterised in that the device is caused to comprise a circulation device for absorbent, arranged to bring absorbent from a first place in the device to a second place in the device, in that the oxygen is added by addition of air to the absorbent at a first point in the circulation device, in that a separation device is caused to separate the gas contained in the absorbent off from the absorbent at a second point, which second point is arranged at a higher level than the first point, before the absorbent is brought back to the second place in the device, and in that a part of the oxygen contained in the air is caused to react with the compound before it reaches the separation device.
- Figure 1 is a cross-sectional view of a device for purifying gas
- FIG. 2 is a detail view in cross-section of a venturi plate. Both figures share the same reference numerals for the same parts.
- the gas streams into the housing 2 via the inlet 3, past the quenching device 5 and into a space which is downwards limited by the surface 14a, and which is essentially upwards limited by the lower side of the venturi device 6. No gas can stream past the venturi device 6 via the quenching device 5, since it is sealed by the absorbent in the filling tray.
- the device is essentially circular symmetric, whereby the housing is designed in the form of a cylinder, along the central axis 2a of which the gas is brought in through the inlet 3.
- figure 1 is presented as a cross- section through the central axis 2a of the cylindrical housing 2.
- the venturi device 6 and the liquid bed 11 are hence arranged in the form of a circular symmetric ring surrounding the centrally arranged inlet conduit 3 above the round, circular symmetric basin 14.
- the housing 2, the venturi device 6, the bed 11 and the basin 14 are coaxially arranged. Such geometry will result in a number of advantages .
- the separation device 16e consists of a water trap through which the absorbent is caused to flow, and from the upper part of which contained nitrogen and other gases are separated.
- the device 1 is equipped with between 4 and 12 riser pipes, according to the above described, evenly distributed along the tube-shaped envelope surface of the housing 2, in order to guarantee an even flow and to avoid large concentration gradients in the absorbent.
- the gas streams through the ven- turi tubes 6a downwards up, in other words against the direction of gravity.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Treating Waste Gases (AREA)
- Gas Separation By Absorption (AREA)
Abstract
Method for adding oxygen to a liquid absorbent in a device (1) for purifying gas, which absorbent comprises at least one compound capable of reacting with oxygen. The invention is characterised in that the device (1) is caused to comprise a circulation device (16) for absorbent, arranged to bring absorbent from a first place in the device (1) to a second place in the device (1), in that the oxygen is added by addition of air to the absorbent at a first point in the circulation device (16), in that a separation device (16e) is caused to separate the gas contained in the absorbent off from the absorbent at a second point, which second point is arranged at a higher level than the first point, before the absorbent is brought back to the second place in the device (1), and in that a part of the oxygen contained in the air is caused to react with the compound before it reaches the separation device (16e).
Description
Method for adding oxygen to a liquid absorbent in a device for purifying gas.
The present method relates to a method for adding oxygen to a liquid absorbent in a device for purifying gas.
The method of the invention is particularly useful for the separation of sulfur dioxide and particles from flue gases from combustion of fossil fuels. Conventionally, several different technologies are used for such flue gas purification, for example venturi scrubbers, bubble beds and spray towers, in which the flue gases are exposed to contact with a liquid absorbent, for example water containing an active ingredient such as lime, whereby the sulfur dioxide and the particles pass over to the absorbent. It is important to maximize the contact surface and time between the flue gases and the absorbent in the purification device for maximum yield. Spray towers are often reliable, but since the drops of absorbent produced in the spray tower are comparatively large, they can only separate a limited part of the sulfur dioxide and the particles from the flue gases, if not built in a number of spraying levels. Therefore, spray towers tend to be very large and therefore expensive at large throughput volumes and high levels of separation.
Venturi scrubbers, on the other hand, produce finer drops that thereby separate a larger part of sulfur dioxide. Howev- er, they are expensive to operate. Bubble beds are also expensive to operate, since relatively large amounts of energy are required, for instance in the form of supplied stirring
RECORD CnrV -TRAKSLATK1V
,;-■ ,e |2.4>
action in order to obtain a good yield, in combination with such beds often having to be quite high.
Thus, there is a need for a way to purify gases from gaseous pollutants and/or pollutants in the form of particles, which is both cheap and efficient, and which does not require all too bulky equipment, especially when it comes to purification of flue gases from fossil fuel combustion. Moreover, when purifying sulfur dioxide from flue gases in scrubbers, using for example lime as the absorbent, it is necessary to add an oxidant, most often air, in order to oxidize the reaction products in the absorbent. This constitutes a problem for purifying flue gases from a so called oxyfuel burner, i.e. an industrial burner or power plant burner which is driven with an oxidant comprising more oxygen and less nitrogen than air. In general, flue gases from such burners comprise a large part carbon dioxide and water vapour, and subsequent carbon dioxide separation steps are in such cases often used. In case air is added to the absorbent, problems do however arise as any subsequent carbon dioxide separation steps must treat the nitrogen added via the air, which nitrogen then is present in the purified gases. Thus, a cost efficient method would be desirable that does not lead to nitrogen gas being added in large quantities to the purified gases.
The present invention solves these problems. Thus, the present invention relates to a method for adding oxygen to a liquid absorbent in a device for purifying gas, which absorbent comprises at least one compound capable of reacting with oxygen, and is characterised in that the device
is caused to comprise a circulation device for absorbent, arranged to bring absorbent from a first place in the device to a second place in the device, in that the oxygen is added by addition of air to the absorbent at a first point in the circulation device, in that a separation device is caused to separate the gas contained in the absorbent off from the absorbent at a second point, which second point is arranged at a higher level than the first point, before the absorbent is brought back to the second place in the device, and in that a part of the oxygen contained in the air is caused to react with the compound before it reaches the separation device.
The invention will now be described in detail, with reference to exemplifying embodiments of the invention and to the appended drawings, in which:
Figure 1 is a cross-sectional view of a device for purifying gas; and
Figure 2 is a detail view in cross-section of a venturi plate. Both figures share the same reference numerals for the same parts.
Figure 1 illustrates a device 1 according to the present invention, by the use of which a method according to the present invention advantageously can be performed. The device 1 comprises a housing 2, an inlet 3 for gas to be purified and one or several outlets 4 for purified gas. The gas, which preferably consists of flue gases from combustion of fossil fuel in an industrial burner or power plant burner, can be hot or already cooled in a previous step (not shown) . The gas is added through inlet 3 using a supply device, which can be a fan device (not shown) arranged upstream or downstream of
device 1, natural pressure from previous process steps or the corresponding .
The housing is preferably manufactured from a rigid material, preferably glass fiber reinforced plastic, metal or concrete with internal rubber coating. The inside of the housing is advantageously either made from plastic, gummed or executed in stainless steel, in order to withstand the chemical conditions inside the device 1.
From the inlet 3, the gas is conveyed on to and past a quenching device 5 that, via nozzles 5a, injects absorbent in the form of liquid jets that are partly reshaped into drops in the gas streaming past the jets. A certain part of the liquid evaporates as the temperature of the gas is lowered, and is conveyed in gaseous form onwards together with the gas to be purified. This will cool the gas to a desired process temperature. Suitable process temperatures after the quenching are between room temperature and 800C, more preferably between 500C and 700C. Moreover, some of the drops are conveyed from the quenching device 5 in liquid phase onwards together with the gas streaming past the jets. Thus, using the quenching device both cooling and saturation is achieved of the gas streaming past, but also drop generation before the subsequent venturi step, which is described in the following.
The gas mixture is thus conveyed onwards to a venturi device 6 in the form of a plate comprising a multitude venturi tubes, arranged in the plate one next to the other and mutually parallel, in the form of through holes. The venturi device 6 is most clearly shown in figure 2, which illustrates venturi tubes βa comprising a centrally arranged constriction
in which the velocity of the gas increases, so that heavy turbulence is achieved when gas streams through the hole.
The gas thus streams 7 from below up to and in through the parallel venturi tubes 6a, at the entrance of which it brings with it liquid drops from a liquid film 8, preferably water and absorbent, arranged on the lower side of the venturi device 6. The drops contained in the gas and originating from the previous quenching, together with liquid carried from the film 8, streams with the gas through the venturi tubes βa, and therein form very small droplets 9 of absorbent because of the heavy turbulence. Since several venturi tubes 6a are used in parallel in this way, a very large contact surface between gas and absorbent, and good dispersion of the drop- lets in the gas, is achieved, resulting in high yield regarding purification of the gas.
In order to further improve the capability of the venturi tubes 6a to form small droplets of the absorbent liquid, it is preferred that each tube 6a comprises a small shoulder 6b at the place for the constriction inside the tube 6a. The shoulder 6b is preferably shaped as a small, abrupt projection from the inner wall of the tube 6a, advantageously in the form of a circular projection, and has the purpose of additionally increasing the turbulence of the gas streaming through the tube 6a.
In order to make sure that the film 8 does not dry up, thereby causing a risk for buildup and clogging, a wetting device 12, for example in the form of a series of spray nozzles, is arranged to continuously wet the lower side of the venturi device 6.
The upper side of the venturi device 6 supports a liquid bed 11 of moving absorbent, which is continuously filled via a filler device 13, for example in the form of a tray. The absorbent pours from the filling device 13, across the upper side of the venturi device 6 and down into a filling tray in the quenching device 5. Thus, the pouring absorbent forms the bed 11 of absorbent above the venturi device 6. At the same time the quenching device 5 is continuously replenished with absorbent, which is sprayed out through nozzles 5a.
After the mixture of gas and small droplets of absorbent have passed the venturi tubes βa, the gas rises up through the liquid bed 11 in the form of bubbles 10. Since the stream of gas/droplet mixture out from the plurality of venturi tubes 6a is heavily turbulent, a good mixture of absorbent in the bed 11 is achieved. This guarantees a very large contact surface between absorbent and gas also in the liquid bed 11, and thereby also high yield in terms of gas purification. The absorbent conveyed by the gas through the venturi tubes βa remains in the liquid bed 11 and is carried with the latter towards the quenching device 5.
The absorbent which is sprayed out as liquid jets from the quenching device 5 is conveyed in part, as described above, in gaseous and liquid phase by the gas streaming past and thereafter again into and through the venturi device 6. The rest of the absorbent instead falls down and is collected in a basin 14 arranged under the quenching device 5.
An overflow device 15 is connected to the filling tray of the quenching device 5, and opens out into the basin 14, so that absorbent is led via the overflow device 15 and down into the
basin in case the surface of the absorbent in the filling tray of the quenching device 5 exceeds above a predetermined level. This leads to that the amount of absorbent used in the quenching device 5 can be kept at a suitable level in a sim- pie way even in case large amounts of absorbent are added from the bed 11.
In order to maintain the liquid level in the bed 11, the filling device 13 is continuously replenished with absorbent via a recirculation system 16 for absorbent liquid, being externally arranged in relation to the housing 2, comprising an exit conduit below the surface 14a of the basin 14. A pump 16a is arranged to pump absorbent from the basin 14, into and up through a riser pipe lβc and via an inlet conduit 16d to the filler device 13, for onwards transport to the liquid bed 11. The operation of the pump 16a is controlled, using a suitable known control device (not shown) , so that a suitable liquid depth is maintained in the liquid bed 11. Alternatively, a suitable known valve device (not shown) in the filler device 13 can be controlled, using the control device, so that a suitable level is maintained in the bed 11. The control system may be connected, on the one hand, to the pump 16a and/or to the valve device, and, on the other hand, to a suitable known level meter (not shown) for liquid level in the bed 11.
It is preferred that the recirculation system 16 is designed with such capacity that all liquid in the basin 14 can be circulated about 25 times per hour.
The gas having been purified in the venturi device β and the liquid bed 11 then streams on to the outlet 4, via a droplet separator 17 which is conventional as such and which is wet-
ted by a wetting device 18 similar to the wetting device 12, with the aim of avoiding buildup and clogging.
Thus, the gas streams into the housing 2 via the inlet 3, past the quenching device 5 and into a space which is downwards limited by the surface 14a, and which is essentially upwards limited by the lower side of the venturi device 6. No gas can stream past the venturi device 6 via the quenching device 5, since it is sealed by the absorbent in the filling tray.
According to the preferred embodiment illustrated in figure 1, the device is essentially circular symmetric, whereby the housing is designed in the form of a cylinder, along the central axis 2a of which the gas is brought in through the inlet 3. In other words, figure 1 is presented as a cross- section through the central axis 2a of the cylindrical housing 2. The venturi device 6 and the liquid bed 11 are hence arranged in the form of a circular symmetric ring surrounding the centrally arranged inlet conduit 3 above the round, circular symmetric basin 14. Furthermore, the housing 2, the venturi device 6, the bed 11 and the basin 14 are coaxially arranged. Such geometry will result in a number of advantages .
In addition to that the construction can be made compact and will be sturdy, the process of applying gum to the inside of the housing, in case such gum is used, is simplified in the case a cylindrical device 1 is used. Moreover, the flow of absorbent liquid and gas will be more favorable, harmful pressure gradients and sedimentation will for example not occur as much as for instance in quadratic or other geometries with corners. The filler device 13 can in a simple way
be arranged essentially around the whole liquid bed, from where absorbent can flow in a symmetric manner outside in, towards one and the same circular symmetric exit constituted by the filling tray of the quenching device 5. In this way, an even and controlled flow of absorbent in the liquid bed 11 is ensured. If so is needed, several outlets 4 for purified gas can also be arranged around the envelope circumference of the housing 2. According to a preferred embodiment, the purification device 1 is designed for purification of between about 80 000 and 1 000 000 Nm3/h gas. To this end, it is preferred that the housing 2 has an inner diameter of between 4 and 15 meters. The distance between the quenching device 5 and the liquid surface 14a, i.e. the height of the passage through which the gas streams on its way between the inlet 3 and the space limited by the liquid surface 14a and the venturi device 6, is preferably between 20 cm and 2 meters. According to a preferred embodiment, the height of the surface of the liquid 14a is adjusted, by adding or removing absorbent using existing filling- and tapping systems, so that the height of said passage is adapted to the amount of gas to be purified per time unit. If the gas stream is decreased, an increase of the liquid level 14a is thus performed, so that the stream through the passage becomes more turbulent and so that the gas therefore brings with it the quenching liquid in a more efficient way. When the gas is bubbled through the liquid bed 11, the latter expands, because of the space which is occupied by the gas bubbles in the liquid, so that the liquid depth in the bed 11 increases. In a non-expanded state, the depth of the liquid
bed 11 is preferably about between 20 and 40 centimeters. In an expanded state, i.e. during full operation, the depth of the liquid bed is preferably about between 1 and 2 meters. This is however heavily dependent upon the desired collection efficiency, the viscosity of the absorbent and other factors.
The plate of the venturi device 6 is, according to a preferred embodiment, between about 50 and 80 millimeters high, and therefore the length of the venturi tubes 6a are also equally tall. The entrances of the tubes 6a in the plate preferably cover about 15% of the bottom surface of the plate, and are preferably arranged evenly distributed across the lower side of the plate. The constriction of each venturi tube is preferably between about 10 and 30 millimeters of diameter, any shoulders 6b not counted. Preferably, the venturi device 6 comprises at least about 100, more preferably at least 500, venturi tubes 6a working in parallel.
Preferably, the plate is manufactured from a rigid and resis- tant material, which is also chemically resistant against the gas and the absorbent. Examples comprise rigid plastics such as polypropylene and acid-proof metals.
According to a preferred embodiment, the device 1 is used for separating sulphur dioxide from flue gases from combustion of fossil fuel, such as natural gas, oil, coal, etc. As absorbent can for this purpose be used for instance water supplemented with lime and/or limestone, which in this case forms a slurry with comparatively high viscosity. Moreover, oxygen may be added to the absorbent, so that the sulphur dioxide finally forms gypsum (CaSO4 • 2H2O) , which may be collected and used later, through the following reaction formulas:
CaCO3 + SO2 "> CaSO3 + CO2
CaSO3 + H2O + ^O2 -> CaSO4 + H2O
According to a preferred embodiment, the absorbent in the basin 14 contains about 97-98% of solid gypsum and about 2-3% of solid limestone in powder form during operation.
In figure 1, there is illustrated a supply conduit 19 for absorbent and a pump 20 for pumping in additional absorbent in the form of for example lime and water in a suitable mixing ratio, into the basin 14. Furthermore, there is an outlet conduit 21 for the reaction products, in combination with an additional pump 22. In the case with the above described reactions, the formed gypsum is separated, and is run through a conventional hydrocyclone (not shown) . Thereafter, the small gypsum crystals are brought back to the device 1, while the larger ones are taken away for further treatment.
A device 1 in accordance with the present invention is also efficient for separating particles from the gas, which particles are then also transported away via the outlet conduit 21.
A sensor device 23, which is known as such, is arranged in the basin 14 with the purpose of measuring the mass ratio between lime and gypsum in the basin 14, for example by measuring the density in the absorbent in the basin 14 and then, based thereupon, to calculate the said mass ratio. On basis of the measured density, the amount of reaction products transported away by the pump 22 is controlled. The amount of lime added is at the same time controlled so that it corresponds to the amount of sulphur separated using the device 1, which amount sulphur is established by measuring the pH in
the absorbent, also using the sensor device 23. The above- mentioned control device is thus arranged to control, by regulating the pump 20, the supply of new lime and liquid to the basin 14 through the supply conduit 19, so that this mass ratio is kept at a constant level. In this way, among other things it is achieved that a change in the gas stream through, and the amount of absorbed SO2 in, the device 1, affecting how quickly the added lime is converted, can be met so that an efficient absorption at all times can be main- tained.
Said control device is also preferably arranged to control the pumps 20, 22, so that the liquid level 14a is such that the distance between the liquid level 14a and the quenching device 5 is suitable for the current stream velocity, as explained above.
It is preferred that the oxidant required to oxidize CaSU3 to CaSO4 according to the above reaction formula is added to the absorbent being transported in the riser pipe 16c, in which the main oxidation of CaSC>3 also takes place. Conveniently, the supply of oxygen takes place via addition of air via a supply conduit lβb at the bottom of the riser pipe 16c. According to a very preferred embodiment, the gas which is to be purified consists of flue gases from an oxyfuel burner, and the gaseous compound contents of the liquid absorbent present in the riser pipe 16c are separated using a separation device 16e at the upper end of the riser pipe, before the absorbent is added to the bed 11, and is transported away from the device 1 via an outlet conduit 16f.
In other words, the oxidant is added to the absorbent in the recirculation device 16 at a first point at the bottom of the riser pipe 16c, and the nitrogen content in the added oxidant is led off from the absorbent at a second point, arranged higher than the first point and before the absorbent again joins the rest of the absorbent in the device 1.
Such an arrangement will secure that sufficient amounts of oxygen can be added to the absorbent during its transport upwards through the riser pipe 16c, at the same time as the contents of the added air of nitrogen, remaining oxygen and other gases that are considered pollutants under the circumstances are not allowed to enter the device 1 and there being mixed with the purified gas. Hence, in this way a cheap way is achieved of avoiding the problems with contained nitrogen in purified flue gases from oxyfuel burners during later carbon dioxide separation steps.
According to a preferred embodiment, the separation device 16e consists of a water trap through which the absorbent is caused to flow, and from the upper part of which contained nitrogen and other gases are separated.
Preferably, the device 1 is equipped with between 4 and 12 riser pipes, according to the above described, evenly distributed along the tube-shaped envelope surface of the housing 2, in order to guarantee an even flow and to avoid large concentration gradients in the absorbent. According to the invention, the gas streams through the ven- turi tubes 6a downwards up, in other words against the direction of gravity. This leads to the advantage that the absorption of pollutants present in the gas to a certain extent can
be made self regulating. Namely, in case the gas stream velocity decreases, the amount of absorbent will to a certain extent penetrate down, against the gas stream, into the ven- turi tubes βa from the bed 11 of absorbent arranged above the venturi tubes βa. This absorbent penetrating downwards will decrease the effective size of the constriction in each respective venturi tube βa, thereby increasing the venturi action in the sense that the turbulence of the gas streaming there through increases, whereby the absorption can be main- tained despite less gas throughput.
Using a method according to the present invention to separate sulphur dioxide from flue gases, a very good mass transfer of sulphur from the gas to the absorbent can be achieved due to a very large total contact surface between gas and absorbent in the quenching device 5, the venturi device 6 and the bed 11. Collecting efficiencies of up to 99% are generally possible to achieve, without the energy costs being higher than for conventional technology. As a comparison, it can be men- tioned that conventional spray towers normally have collecting efficiencies of about 85-95%, in certain cases up to 97- 98%. Moreover, it is possible to design a device according to the present invention, for carrying out such a method, in a compact and non-bulky way, and which at the same time re- quires a minimal supply of energy since there is no need for heating and since the energy requirements for the circulation of absorbent is limited.
Furthermore, flue gases from oxyfuel burners can be treated cheaply and reliably without nitrogen being added to the purified gas, thereby complicating subsequent carbon dioxide separation steps.
Above, preferred embodiments have been described. However, it is apparent to the skilled person that many modifications can be made to the described embodiments without departing from the idea of the invention. Thus, the invention shall not be limited to the described embodiments, but can be varied within the scope of the enclosed claims.
Claims
1. Method for adding oxygen to a liquid absorbent in a device (1) for purifying gas, which absorbent comprises at least one compound capable of reacting with oxygen, ch a ra c te r i s ed i n that the device (1) is caused to comprise a circulation device (16) for absorbent, arranged to bring absorbent from a first place in the device (1) to a second place in the device (1) , in that the oxygen is added by addition of air to the absorbent at a first point in the circulation device (16), in that a separation device (16e) is caused to separate the gas contained in the absorbent off from the absorbent at a second point, which second point is arranged at a higher level than the first point, before the absorbent is brought back to the second place in the device (1), and in that a part of the oxygen contained in the air is caused to react with the compound before it reaches the separation device (16e) .
2. Method according to claim 1, ch a r ac te r i s ed i n that the device (1) is arranged to separate SO2 contained in the gas by transformation to CaSU3 and thereafter to CaS04, in that the transformation to CaSθ3 is caused to be achieved by reaction between the gas and lime and/or limestone com- prised in the absorbent, and in that the transformation to CaS04 is caused to take place by reaction, between the first point and the second point in the circulation device (16), between the gas and the added oxygen.
3. Method according to claim 1 or 2, c h a r a c t e r i s e d i n that the gas is caused to consist of flue gases from an industrial burner or power plant burner.
4. Method according to claim 3, c h a r a c t e r i s e d i n that the gas is caused to consist of flue gases from an oxyfuel burner.
5. Method according to any one of the preceding claims, ch ar a c te r i s ed i n that the separation device (16e) is caused to be a water trap through which the absorbent is caused to flow, and from the upper part of which contained nitrogen and other gases are caused to be sepa- rated.
6. Method according to any one of the preceding claims, char ac te r i s ed i n that the circulation device (16) is caused to be arranged to maintain a level of absorbent in a liquid bed (11) of absorbent by bringing absorbent from an absorbent container (14), arranged at a lower level, and in that the device (1) is caused to bring absorbent from the bed (11) to the container (14) .
7. Method according to claim 6, c h a r a c t e r i s e d i n that the first and second points are connected by a vertical riser pipe (16c) up through which the absorbent is pumped.
8. Method according to claim 6 or 7, ch a r ac te r i s ed i n that the circulation device (16) is designed with a capacity such that all liquid in the container (14) can be turned over about 25 times per hour.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
RU2012103451/04A RU2532265C2 (en) | 2009-07-14 | 2010-07-13 | Method of adding oxygen to liquid absorbent in device for gas purification |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE0950559A SE533938C2 (en) | 2009-07-14 | 2009-07-14 | Method and apparatus for purifying gases |
SE0950559-5 | 2009-07-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011008159A1 true WO2011008159A1 (en) | 2011-01-20 |
Family
ID=43449589
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE2010/050619 WO2011008155A1 (en) | 2009-07-14 | 2010-06-04 | Method and device for purifying gases by absorption |
PCT/SE2010/050840 WO2011008159A1 (en) | 2009-07-14 | 2010-07-13 | Method for adding oxygen to a liquid absorbent in a device for purifying gas |
PCT/SE2010/050841 WO2011008160A1 (en) | 2009-07-14 | 2010-07-13 | Plate arranged to support a bed of liquid absorbent in a device for puryfing gas |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE2010/050619 WO2011008155A1 (en) | 2009-07-14 | 2010-06-04 | Method and device for purifying gases by absorption |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE2010/050841 WO2011008160A1 (en) | 2009-07-14 | 2010-07-13 | Plate arranged to support a bed of liquid absorbent in a device for puryfing gas |
Country Status (5)
Country | Link |
---|---|
EP (3) | EP2889075B1 (en) |
PL (2) | PL2454005T3 (en) |
RU (3) | RU2532435C2 (en) |
SE (1) | SE533938C2 (en) |
WO (3) | WO2011008155A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104307342A (en) * | 2014-11-07 | 2015-01-28 | 广西南宁华国环境科技有限公司 | Two-stage flue gas desulfurizing tower |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2705537T3 (en) | 2013-03-28 | 2019-03-25 | Basf Se | Production of pyripyropenes from dry biomass |
CN110115920B (en) * | 2019-06-18 | 2021-07-13 | 宁夏峰业环保科技有限公司 | Anti-reflux and shunting bubbling pipe for desulfurizing tower |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0815923A2 (en) * | 1996-06-28 | 1998-01-07 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for controlling oxidation in flue gas desulfurization |
WO2003004137A1 (en) * | 2001-07-05 | 2003-01-16 | Alstom (Switzerland) Ltd. | A method and a device for the separation of sulphur dioxide from a gas |
WO2005007274A1 (en) * | 2003-06-26 | 2005-01-27 | Alstom Technology Ltd | A method and a device for the separation of sulphur dioxide from a gas |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB357599A (en) * | 1929-04-22 | 1931-09-22 | Industrikemiska Ab | Improvements in methods of and bubbling apparatus for treating liquids with gases |
US4141701A (en) * | 1975-11-28 | 1979-02-27 | Lone Star Steel Company | Apparatus and process for the removal of pollutant material from gas streams |
US4078048A (en) * | 1977-02-16 | 1978-03-07 | Combustion Equipment Associates, Inc. | Process and apparatus for removing sulfur from stack gases in the form of elemental sulfur |
US4246245A (en) * | 1979-01-02 | 1981-01-20 | Bechtel International Corporation | SO2 Removal |
JPS5898126A (en) * | 1981-12-03 | 1983-06-10 | Ishikawajima Harima Heavy Ind Co Ltd | Desulfurization of stack gas |
DE3441442A1 (en) * | 1984-11-13 | 1986-05-15 | Knauf-Research-Cottrell GmbH & Co Umwelttechnik KG, 8715 Iphofen | METHOD FOR IMPLEMENTING GAS WITH SUSPENSIONS |
RU2040957C1 (en) * | 1993-02-09 | 1995-08-09 | Акционерное общество "Новатор" | Bubbling absorber |
JP2715059B2 (en) * | 1994-05-06 | 1998-02-16 | 韓国電力公社 | Method and apparatus for flue gas and desulfurization |
GB2296490B (en) * | 1994-05-11 | 1998-04-08 | Babcock Hitachi Kk | Wet-type flue gas desulfurization plant and method making use of a solid desulfurizing agent |
SE502925C2 (en) * | 1994-06-23 | 1996-02-19 | Abb Flaekt Ind Ab | Methods and apparatus for removing sulfur dioxide from a gas |
US5665317A (en) * | 1995-12-29 | 1997-09-09 | General Electric Company | Flue gas scrubbing apparatus |
US5906773A (en) * | 1997-07-30 | 1999-05-25 | Norton Company | Liquid distributor |
EP1366796A3 (en) * | 1997-11-11 | 2004-01-07 | Mitsubishi Heavy Industries, Ltd. | A wet gas processing method and the apparatus using the same |
US6066304A (en) * | 1998-08-06 | 2000-05-23 | Delores Pircon | Process for removing sulfur dioxide out of a gas |
JP2002306958A (en) * | 2001-04-11 | 2002-10-22 | Kansai Electric Power Co Inc:The | Gas liquid contact plate and gas liquid contact apparatus |
US6752854B1 (en) * | 2002-12-16 | 2004-06-22 | Graham Packaging Company, L.P. | Venturi scrubber plate, waste capture system, and method |
RU2256603C1 (en) * | 2004-04-13 | 2005-07-20 | Открытое Акционерное Общество "Всероссийский теплотехнический научно-исследовательский институт" (ОАО "ВТИ") | Method for treatment of smoke gas from sulfur dioxide |
FR2893669B1 (en) * | 2005-11-18 | 2008-01-11 | Lab Sa Sa | WASHER FOR EXHAUST GAS PURIFICATION OF A DIESEL ENGINE, METHOD FOR CARRYING OUT THE SAME, AND CORRESPONDING MARINE VEHICLE |
US7560084B2 (en) * | 2007-03-30 | 2009-07-14 | Alstom Technology Ltd | Method and device for separation of sulphur dioxide from a gas |
-
2009
- 2009-07-14 SE SE0950559A patent/SE533938C2/en not_active IP Right Cessation
-
2010
- 2010-06-04 WO PCT/SE2010/050619 patent/WO2011008155A1/en active Application Filing
- 2010-06-04 EP EP15155371.6A patent/EP2889075B1/en active Active
- 2010-06-04 PL PL10800111T patent/PL2454005T3/en unknown
- 2010-06-04 PL PL15155371T patent/PL2889075T3/en unknown
- 2010-06-04 EP EP15155320.3A patent/EP2889074A1/en not_active Withdrawn
- 2010-06-04 EP EP10800111.6A patent/EP2454005B8/en active Active
- 2010-06-04 RU RU2012103453/05A patent/RU2532435C2/en not_active IP Right Cessation
- 2010-07-13 RU RU2012103450/02A patent/RU2532607C2/en not_active IP Right Cessation
- 2010-07-13 WO PCT/SE2010/050840 patent/WO2011008159A1/en active Application Filing
- 2010-07-13 RU RU2012103451/04A patent/RU2532265C2/en not_active IP Right Cessation
- 2010-07-13 WO PCT/SE2010/050841 patent/WO2011008160A1/en active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0815923A2 (en) * | 1996-06-28 | 1998-01-07 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for controlling oxidation in flue gas desulfurization |
WO2003004137A1 (en) * | 2001-07-05 | 2003-01-16 | Alstom (Switzerland) Ltd. | A method and a device for the separation of sulphur dioxide from a gas |
WO2005007274A1 (en) * | 2003-06-26 | 2005-01-27 | Alstom Technology Ltd | A method and a device for the separation of sulphur dioxide from a gas |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104307342A (en) * | 2014-11-07 | 2015-01-28 | 广西南宁华国环境科技有限公司 | Two-stage flue gas desulfurizing tower |
Also Published As
Publication number | Publication date |
---|---|
RU2532607C2 (en) | 2014-11-10 |
RU2532435C2 (en) | 2014-11-10 |
EP2454005B8 (en) | 2015-07-29 |
RU2012103450A (en) | 2013-08-20 |
EP2889075B1 (en) | 2020-11-04 |
EP2454005A4 (en) | 2013-03-13 |
EP2454005A1 (en) | 2012-05-23 |
RU2012103451A (en) | 2013-08-20 |
SE0950559A1 (en) | 2011-01-15 |
EP2454005B1 (en) | 2015-04-01 |
EP2889075A1 (en) | 2015-07-01 |
WO2011008155A1 (en) | 2011-01-20 |
PL2454005T3 (en) | 2015-08-31 |
RU2532265C2 (en) | 2014-11-10 |
WO2011008160A1 (en) | 2011-01-20 |
EP2889074A1 (en) | 2015-07-01 |
RU2012103453A (en) | 2013-08-20 |
SE533938C2 (en) | 2011-03-08 |
PL2889075T3 (en) | 2021-05-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5674459A (en) | Hydrogen peroxide for flue gas desulfurization | |
KR0156354B1 (en) | Wet type flue gas desufurization apparatus | |
CN106166434B (en) | A kind of ozone oxidation double tower ammonia process of desulfurization denitrating technique and its system | |
WO2011140820A1 (en) | Wet flue gas desulfurization absorption tower for power plant | |
SI9520025A (en) | Flue gas scrubbing apparatus | |
US8226754B2 (en) | Low cost wet lime/limestone/sodium FGD system | |
JP2018023967A (en) | Desulfurization process based on ammonia via ammonia addition in different chambers and device | |
CN103203175B (en) | Flue gas desulfurization and denitration process and device for recovering ammonium sulfate | |
CN104258719A (en) | Desulfuration, denitration and dust removal (PM2.5 removal) three-in-one technical system for boiler exhaust gas by adopting ammonia method | |
US6695018B2 (en) | Collection scoop for flue gas desulfurization systems with bleed streams or ex situ forced oxidation | |
JP2004533923A (en) | Method and apparatus for separating sulfur dioxide from gas | |
EP2889075B1 (en) | Plate arranged to support a bed of liquid absorbent in a device for purifying gas | |
US7560084B2 (en) | Method and device for separation of sulphur dioxide from a gas | |
US4702893A (en) | Acid air pollution precipitators | |
CN102274688B (en) | Multistage spray absorbing device with high efficiency | |
CN103415598A (en) | Method and apparatus for treating a raw UCG product stream | |
CN105889960A (en) | Flue gas desulfurization device for coal-fired boiler | |
EP3769835A1 (en) | Flue gas desulfurization device | |
CN204170616U (en) | Process of desulfurization for boiler flue gas denitration dust collecting Trinity process system | |
CN205903785U (en) | Spray column and SOx/NOx control system | |
JP4094694B2 (en) | Jet bubbling reactor for flue gas desulfurization | |
JPH10165758A (en) | Flue gas desulfurization process and its device | |
JP6985084B2 (en) | Desulfurization method and desulfurization equipment for gases containing sulfur oxides | |
CN2518573Y (en) | Flue gas desulfurizing packed tower | |
JPH0256127B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10800115 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012103451 Country of ref document: RU |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 10800115 Country of ref document: EP Kind code of ref document: A1 |